Hard bump day after injection

I'm low-key freaking out and need to know if this is normal.

So I've been in T for about 5 months now and this is the first time I've noticed a firm bump where my injection sight was. I usually inject on either side of my stomach, switching back in forth every two weeks as was recommend by my doctor. I'm just now noticing a hard bump where my injection sight was. Maybe this always happens and I just don't pay attention but idk.

Is that normal? Have you experienced it? What should I do if it's not good.